Characterizing the protolunar disk of the accreting companion GQ Lupi B

Abstract

GQ Lup B is a young and accreting, substellar companion that appears to drive a spiral arm in the circumstellar disk of its host star. We report high-contrast imaging observations of GQ Lup B with VLT/NACO at 4-5 $\mu$m and medium-resolution integral field spectroscopy with VLT/MUSE. The optical spectrum is consistent with an M9 spectral type, shows characteristics of a low-gravity atmosphere, and exhibits strong H$\alpha$ emission. The $H-M^{\prime }$ color is $\gtrsim$1 mag redder than field dwarfs with similar spectral types and a detailed analysis of the spectral energy distribution (SED) from optical to mid-infrared wavelengths reveals excess emission in the $L^{\prime }$, NB4.05, and $M^{\prime }$ bands. The excess flux is well described by a blackbody component with $T_{\mathrm{disk}}\approx 460$ K and $R_{\mathrm{disk}}\approx 65R_{\mathrm{J}}$ and is expected to trace continuum emission from small grains in a protolunar disk. We derive an extinction of $A_V\approx 2.3$ mag from the broadband SED with a suspected origin in the vicinity of the companion. We also combine 15 yr of astrometric measurements and constrain the mutual inclination with the circumstellar disk to $84\pm 9$ deg, indicating a tumultuous dynamical evolution or a stellar-like formation pathway. From the measured H$\alpha$ flux and the estimated companion mass, $M_{\mathrm{p}}\approx 30M_{\mathrm{J}}$, we derive an accretion rate of $\dot{M}\approx 10^{-6.5}{M}_{\mathrm{J}}{\mathrm{yr}}^{-1}$. We speculate that the disk is in a transitional stage in which the assembly of satellites from a pebble reservoir has opened a central cavity while GQ Lup B is in the final stages of its formation.

28 pages, 11 figures, accepted for publication in AJ

References in corpus (65)

• The Gaia mission
• The MUSE second-generation VLT instrument
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Two accreting protoplanets around the young star PDS 70
• An Optical Spectroscopic Study of T Tauri Stars. I. Photospheric Properties
• UV excess measures of accretion onto young very low-mass stars and brown dwarfs
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• The Data Processing Pipeline for the MUSE Instrument
• On the diversity and statistical properties of protostellar discs
• Towards Chemical Constraints on Hot Jupiter Migration
• A Circumplanetary Disk Around PDS70c
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• A statistical test for Nested Sampling algorithms
• The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Discovery of a warm, dusty giant planet around HIP65426
• Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
• Accreting Circumplanetary Disks: Observational Signatures
• orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community
• First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
• MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 $\mu$m. I. Photometric analysis of $\beta$ Pic b, HIP 65426 b, PZ Tel B and HD 206893 B
• Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
• The polarimetric imaging mode of VLT/SPHERE/IRDIS II: Characterization and correction of instrumental polarization effects
• Characterizing 51 Eri b from 1-5 $\mu$m: a partly-cloudy exoplanet
• BOSS Ultracool Dwarfs I: Colors and Magnetic Activity of M and L dwarfs
• The polarimetric imaging mode of VLT/SPHERE/IRDIS I: Description, data reduction and observing strategy
• Misaligned Protoplanetary Disks in a Young Binary System
• Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893
• The slow spin of the young sub-stellar companion GQ Lupi b and its orbital configuration
• Keck/NIRC2 $L$'-Band Imaging of Jovian-Mass Accreting Protoplanets around PDS 70
• A Panchromatic View of Brown Dwarf Aurorae
• Evidence for a circumplanetary disk around protoplanet PDS 70 b
• SPHERE IRDIS and IFS astrometric strategy and calibration
• Accretion Properties of PDS 70b with MUSE
• Long period planets from dynamical relaxation
• Astrometric follow-up observations of directly imaged sub-stellar companions to young stars and brown dwarfs
• A survey of the linear polarization of directly imaged exoplanets and brown dwarf companions with SPHERE-IRDIS. First polarimetric detections revealing disks around DH Tau B and GSC 6214-210 B
• Astrometric and photometric monitoring of GQ Lup and its sub-stellar companion
• Scattered light mapping of protoplanetary disks
• ALMA Measurements of Circumstellar Material in the GQ Lup System
• GQ Lup B Visible & Near-Infrared Photometric Analysis
• First High-Contrast Science with an Integral Field Spectrograph: the Sub-Stellar Companion to GQ Lup
• Spectral and orbital characterisation of the directly imaged giant planet HIP 65426 b
• Near-IR integral-field spectroscopy of the companion to GQ Lup
• Comparison of planetary Hα-emission models: A new correlation with accretion luminosity
• Strong H$\alpha$ emission and signs of accretion in a circumbinary planetary mass companion from MUSE
• An ALMA and MagAO Study of the Substellar Companion GQ Lup B
• Molecular mapping of the PDS70 system: No molecular absorption signatures from the forming planet PDS70 b
• Early ComeOn+ Adaptive Optics Observation of GQ Lup and its Substellar Companion
• GRAVITY K-band spectroscopy of HD 206893 B: brown dwarf or exoplanet
• An Explanation of the Very Low Radio Flux of Young Planet-mass Companions
• Upper limits on protolunar disc masses using ALMA observations of directly-imaged exoplanets
• ALMA 0.88 mm Survey of Disks around Planetary-mass Companions
• Satellitesimal Formation via Collisional Dust Growth in Steady Circumplanetary Disks
• SCExAO and GPI $YJH$ Band Photometry and Integral Field Spectroscopy of the Young Brown Dwarf Companion to HD 1160
• Biases in orbit fitting of directly-imaged exoplanets with small orbital coverage
• 2MASS J15491331-3539118: a new low-mass wide companion of the GQ Lup system
• Observing the gas component of circumplanetary disks around wide-orbit planet-mass companions in the (sub)mm regime
• Keck/OSIRIS Pa$\beta$ high-contrast imaging and updated constraints on PDS~70b
• Combining angular differential imaging and accurate polarimetry with SPHERE/IRDIS to characterize young giant exoplanets
• Spectral appearance of the planetary-surface accretion shock: Global spectra and hydrogen-line profiles and fluxes
• CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion
• Hints of a Population of Solar System Analog Planets from ALMA
• The disk of 2MASS 15491331-3539118 = GQ Lup C as seen by HST and WISE
• Detection of H$\alpha$ emission from PZ Tel B using SPHERE/ZIMPOL

Cited by in corpus (14)

• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• HST/WFC3 H$\alpha$ Direct-Imaging Detection of a Point-like Source in the Disk Cavity of AB Aur
• The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES${}^{+}$
• Emission line variability of young 10-30 Mjup companions : I. The case of GQ Lup b and GSC 06214-00210 b
• Resolved near-UV hydrogen emission lines at 40-Myr super-Jovian protoplanet Delorme 1 (AB)b: Indications of magnetospheric accretion
• ALMA Discovery of a Disk around the Planetary-mass Companion SR 12 c
• The ESO SupJup Survey IV. Unveiling the carbon isotope ratio of GQ Lup B and its host star
• Detectability of satellites around directly imaged exoplanets and brown dwarfs
• Machine Learning for Exoplanet Detection in High-Contrast Spectroscopy: Revealing Exoplanets by Leveraging Hidden Molecular Signatures in Cross-Correlated Spectra with Convolutional Neural Networks
• JWST/MIRI observations of the young TWA 27 system: hydrocarbon disk chemistry, silicate clouds, evidence for a CPD
• The ExoGRAVITY survey: A K-band spectral library of giant exoplanet and brown dwarf companions
• Monitoring H$\alpha$ Emission from the Wide-orbit Brown-dwarf Companion FU Tau B
• Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions
• Occurrence rates of accreting companions from a new method for computing emission-line survey sensitivity: application to the H-alpha Giant Accreting Protoplanet Survey